Method and apparatus for utilizing waste heat



Dec. 31, 1929. H. B. SMITH 7 METHOD AND APPARATUS FOR UTILIZING WASTEHEAY Filed April 6, 1927 i ll ll l h l' INVENTOR ATTORN EYS PatentedDec. 31, 1929 UNEED STATES PATENT orricn HERMAN B. SMITH, OF PLAINFIELD,NEW JERSEY, ASSIGNOR TO THE BABCOCK & WIL- GOX COMPANY, OF BAYONNE, NEWJERSEY, A CORPORATION OF NEW JERSEY METHOD" AND APPARATUS FOR UTILIZINGWASTE HEAT Application filed April 6, 1927. Serial No. 181,337.

My present invention relatesto means and methods applicable to theutilization of heat from hot cement clinker and the like, and will bebest understood from the following description and accompanying drawingsshowing illustrative apparatus for carrying out the process or processescontemplated under my invention.

The drawing shows in the only figure a diagrammatic representation of avertical crosssection through a cement kiln and heat utilizing means.

Like reference characters indicate like parts in the drawing.

In the construction shown, the glowing hot calcined material or clinkerfrom the chamber of one of a number of rotary cement kilns 10 isprogressively discharged into the upper end of a vertical passageway orchute 12. The fall of the clinker is checked at the top of the chute bya series of staggered inclined shelves or baflles 1 1, each extendingmore than halfway across the chute from the opposite sides. Theaccumulation of clinker effect, a partition of gas seal, separating thespace in the upper part of the chute 12 from that in the lower part ofthe chute 12, where air is tending to rise because of draft or forcedpressure in the zone of combustion in the kiln 10 above.

An inclined surface 15 receives the clinker falling in the chute 12 anddeflects it in a horizontal direction to enter an inclined rotary cooler16. In the cooler, the hot clinker is rotated and tumbled to bring itinto intimate contact with the cold air current entering the opening 17at the lower end. The cooled clinker is discharged through the opening17 to a place of storage to wait for the final grinding process.-

Air is drawn upwardly, as noted, through the rotary cylinder 16 and thechute 12, to cool the hot clinker which is moving in the oppositedirection. The air is thereby heated. It is drawn from the chute 12through an opening 18 in the side of the chute and enters a boiler 19.The boiler 19 is located, as shown, above the rotary cooler or coolers16 and below the kiln room floor 20. The boiler moving downwardly on thebattles forms, in

may be of any size or any type, a water tube boiler being shown. It maybe located in any position conveniently associated with the chute 12 andthe rotary cylinder 16. Preferably, however, it is located above thecooler with the opening 18 from the chute 12 at the lower part of theboiler setting. If a superheater is used, it may be placed, as shown at19, directly opposite the opening 18 so that it may be contacted withthe hot air before it has been cooled by contact with the boiler heatingsurface.

The air is drawn through and from the boiler by the suction of a fan 21acting at the end ofa flue pipe 22. The air delivered by the fan isconducted by a main pipe 23 to a manifold or header pipe 24:. Thismanifold is tapped to deliver the air through an air pressure pipe 25 toa burner nozzle 26 which discharges fuel and the partially cooled airfromthe boiler into a kiln 10. Any portion or all of the air from theboiler may be thus used.

A powderedfuel feeding device 28 is connected to the pipe 25 anddischarges fuel into the pipe 25 adjacent the nozzle 26. The fuelconnection enters the pipe 25 at a sufficient. distance from the nozzleto insure a good mixing of the fuel in the air blast. The flame from thenozzle 26 enters the kiln to burn and calcine or clinker the cementmixture fed into the kiln atits other and higher end.

By the count'erflow arrangement by which the air is made to flow in adirection opposite to that of the heated material, the greatestefliciency of heat transfer is provided and, at the same time, thetemperature of the air entering the boiler setting is relatively highbecause, just before entering the boiler setting, it contacts with hotmaterial which has not been previously cooled by having cold air drawnover or through it;

It will be obvious that various modifications may be made in theconstruction of the heat reclaimingdevice or in the steps of the processwithout departing from the spirit of this invention.

1' claim:

1. The 'methodof reclaimin 1 heat from hot divided solid non-combustiblematerial comprising the steps of heating air by moving the same througha falling stream of the hot material, passing the heated air over boilerheatin surface, mixing the partially cooled air from the boiler withoutagain contacting it with the hot material with finely divided fuel andburning the mixture in the production of an additional quantity of saidhot material.

2. The method of reclaiming heat from hot divided solid non-combustiblematerial comprising the steps of dischargng the hot material into adownwardly directed passageway and through an outlet therefrom whilesimultaneously drawing air upwardly from said outlet through saidpassageway and from said passageway through. a. heat reclaiming means,mixing the air with finely divided fuel and burning the mixture to heatan additional quantity of the material 3. Apparatus for the recovery ofheat from cement clinker or the like comprising, in combination, adownwardly directed passageway arranged to receive the clinkerdischarged from a kiln, an outlet from said passageway at the lowestpart thereof, a boiler, an outlet from said passageway to said boiler,means for moving air in through said first-mentioned outlet and throughthe falling shower of clinker and said second mentioned outlet over theheating surface of the boiler.

4. Apparatus for the recovery of heat from cement clinker or the likecomprising, in combination, a downwardly directed passageway arranged toreceive the clinker discharged from a kiln, an outlet from saidpassageway at the lowest part thereof, a boiler, an outlet from saidpassageway to said boiler, means for moving air in through saidfirstmentioned outlet and said second mentioned outlet through thefalling shower of clinker and over the heating surface of the boiler,and means for mixing at least a portion of the partially cooled air withfinely divided fuel and injecting and burning the mixture in a kiln.

5. Apparatus for the recovery of heat from cement clinker or the likecomprising, in combination, a vertically disposed passageway arranged toreceive the clinker discharged from a kiln, an outlet from saidpassageway at the lowest part thereof, baffles arranged adjacent the topof the passageway to check the flow of the clinker and to seal againstgas flow at the top of the passageway, the lower portion of saidpassageway being free, and means to move air through said outlet andthrough the free portion of said passageway to cool the falling clinker.

6. Heat interchanging apparatus, comprising a kiln arranged tocontinuously discharge hot clinker from one end, a downwardly directedpassageway for receiving the discharge from said kiln, said passagewayhaving an outlet for clinker at the lower end thereof and a secondoutlet between said first outlet and the upper end of said passageway, aboiler communicating with said second outlet, means to move air into thepassageway through said clinker outlet and from said second outlet overthe heating surface of the 'boiler, and means arranged to mix fuel withthe partially cooled air from the boiler heating surface and inject andburn the mixture in the kiln.

7. In combination, a cement kiln, a downwardly direct-ed clinker cooler,a passageway for conveying hot clinker from the kiln to the cooler, aboiler associated with said kiln and cooler, and means to move air overthe hot clinker while it is freely falling in said cooler, then throughsaid passageway and over the heating surface of the boiler.

S. In combination, a cement kiln. having a fuel burner, a downwardlyext-ending clinker cooler, a passageway for conveying hot clinker fromthe kiln to the cooler, a boiler associated with said kiln and cooler,means to move air over the hot clinker while it is freely falling insaid cooler, then through said passageway and over the heating surfaceof the boiler, and means to deliver the partially cooled air from saidheating surface to said burner.

HERMAN B. SMITH.

